Cooling tower integrated inlet louver fill

ABSTRACT

A fill sheet arrangement in a direct heat exchange section of a cooling tower is provided. Each fill sheet includes ridges, grooves, separators, and an air inlet louver zone itself having ridges, grooves and separators, that improve the performance of the fill sheet arrangement when installed as a direct heat exchange section of a cooling tower. The air inlet louver zone improves the air flow capabilities and performance of the direct heat exchange section by limiting the evaporative liquid from leaving the fill sheet.

This application is a continuation-in-part of U.S. application Ser. No.14/529,941, filed Oct. 31, 2014.

BACKGROUND OF THE INVENTION

The present invention relates to air inlet louver zone of heat and masstransfer media, or fill sheet arrangement within the direct heatexchange portion of a cooling tower. More particularly, the presentinvention relates to inlet louver zone attached to a fill sheet that isused in a direct heat exchange unit, which could be a cooling tower.

The heat and mass transfer media, or fill sheet arrangement, isgenerally vertically oriented with an evaporative liquid, usually water,coursing over the material, usually flowing downwardly, with an airstream directed usually transversely but potentially concurrent or crosscurrent through the spaced fill sheet direct cooling section. The airinteracts with the evaporative liquid for heat and mass transfer.

The integrated air inlet louver zone, hereafter called louver zone, isattached to an edge of fill sheet, is a part of fill sheet, directsairstream to fill sheet, and limits evaporative fluid from leaving thefill sheet beyond the fill sheet edge.

When a pair of fill sheets are stacked a gap forms between two fillsheets' evaporative areas but a plurality of air tunnels forms betweentwo fill sheets' louver zones. These air tunnels, which are generallyhexagonal in shape, form a straight pattern that matches well to the gapcontour between the pair of fill sheets. Multiple repeats of the pair offill sheets form a fill pack, and multiple repeats of a pair of louverzones form a louver pack within a fill pack.

The louver pack prevents evaporative liquid from splashing out of thefill pack. The louver zone's plurality of ridges and grooves are slopeddownward toward the evaporative area so that the evaporative liquid thatis splashed on to the louver zone is flowed back toward the evaporativearea of the fill pack.

To prevent evaporative liquid from falling between two adjacent louverzones, one louver zone's plurality of ridges must align and touchadjacent louver zone's plurality of grooves so that there is no gapbetween the plurality of ridges and the plurality of grooves. Otherwise,two adjacent louver zones can nest and a large gap between louver zonescan form within the louver pack. In this invention, during stacking, twoadjacent inlet louvers are guided into an aligned location by the maleindexer of the first louver zone riding on one of the guide walls of thesecond louver zone so that a plurality of fill sheet spacers located inthe evaporative area can easily lock in the fill sheets in place withrespect to each other.

For best thermal performance of a cooling tower, it is critical that theevaporative areas of the fill pack receive well distributed air streamsfrom their louver pack. In this invention, a plurality of male indexerswithin the louver pack is designed so the male indexers can bepositioned inside the plurality of air tunnels while preserving both thehexagonal shape and the straight pattern of a plurality of air tunnelsthat match so well to the gap opening shape of the evaporative areas.

For best thermal performance of a cooling tower, it is also criticalthat louver pack's plurality of indexing features does not incursignificant air pressure drop by blocking the cooling air that travelstoward the evaporative areas of the fill pack. Air pressure drop iscaused by traveling air blocked by an object with a cross sectionalarea. A larger cross sectional area blocks more air and causes higherpressure drop. This invention uses a plurality of recessed ridges in thelouver pack to decrease the size of overall cross sectional area ofplurality of indexing features. A recessed ridge is located inside oneof plurality of air tunnels that also houses one of plurality of maleindexers. The recessed ridge lowers a small portion of the ridge of theair tunnel so that the male indexer inside the air tunnel does not haveto be so tall to reach the ridge of the air tunnel. A shorter maleindexer has a smaller cross sectional area, when viewed from the airtunnel opening, than a taller male indexer, and the smaller crosssectional area allows larger air passageways on both sides of shortermale indexer. A small increase in the air blockage by adding of therecessed ridge in the air tunnel is more than offset by the largeincrease in the air passageways. Because fill sheets, which includelouver zones and a plurality of male indexers, are made from thermalforming of thin sheets of plastic, all of the fill sheet featuresrequire a draft angle of a minimum of 15°˜17°. By using the recessedridge, the cross sectional area of the male indexers can be decreasedwhile maintaining the minimum draft angle.

In order to further reduce the pressure drop within the air tunnel, thisinvention also uses curved ridge cutouts and air bypasses. In one ofplurality of air tunnels that houses a male indexer, a pair of curvedridge cutouts is made to two opposing tunnel walls near the base of themale indexer. These curved ridge cutouts in the air tunnel increase thesize of air passageways and allow air to go around the male indexerfreely and with only a minimum air pressure drop. These curved ridgecutouts start near the base of a male indexer and opens up toward theplane of a plurality of ridges at an angle that ranges from 30° to 60°such that a portion of the two ridges at the top of the curved ridgecutouts are lowered slightly and two bypass openings are formed betweenthe male indexer tunnel and its two adjacent tunnels. These two bypassopenings allow air to travel through from two adjacent tunnels to themale indexer tunnel so that the air distribution going into the fillpack is better maintained than the design without the bypass openings.

SUMMARY OF THE INVENTION

The invention made improvements to the air inlet louver zone included inthe fill sheet near the first side edge of the fill sheet arrangement.Each fill sheet includes an air inlet louver zone comprised of aplurality of gradually raised surfaces that lead to form a plurality ofraised ridges of each fill sheet. A pair of air inlet louver zonesstacked together forms a plurality of air tunnels between two air inletlouver zones.

The invention made improvements, more specifically, to the indexingfeature inside one of plurality of air tunnels. The invention' indexingfeature comprises a male indexer that aids alignment of louver zonesduring stacking, a pair of curved ridge cutouts made to the air tunnelwalls in order to both minimize the air pressure drop and create bypassopenings to adjacent tunnels, a recessed ridge to minimize the crosssectional area of the male indexer in order to minimize the air tunnelblockage thereby increasing the size of air passageways, and two guidewalls that are attached to the recessed ridge to guide the male indexertoward the recessed ridge. These components working together improve thestacking of the fill sheets while maintaining the nice distribution ofair streams going into the fill pack's evaporative area.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is a side view of a first fill sheet in accordance with anembodiment of the present invention;

FIG. 2 is a partial view of a first inlet louver zone showing a maleindexer and adjacent raised surfaces in accordance with an embodiment ofthe present invention;

FIG. 2a is a partial view of a first inlet louver zone showing anenlarged plan view of a male indexer and adjacent raised surfaces inaccordance with an embodiment of the present invention;

FIG. 2b is a partial view of a first inlet louver zone showing anenlarged isometric view of a male indexer and adjacent raised surfacesin accordance with an embodiment of the present invention;

FIG. 3 is a partial view of a first inlet louver zone showing a maleindexer and curved ridge cutouts in adjacent raised surfaces inaccordance with an embodiment of the present invention;

FIG. 4 is a perspective side view of a second fill sheet in accordancewith an embodiment of the present invention;

FIG. 5 is a partial view of a second fill sheet showing second inletlouver zone in accordance with an embodiment of the present invention;

FIG. 6A is a schematic view of a portion of a first and second inletlouver zone showing a male indexer in accordance with an embodiment ofthe present invention;

FIG. 6B is a view of a portion of a first and second inlet louver zoneshowing a male indexer in accordance with an embodiment of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1 of the drawings, a first fill sheet is shown at10 and a first inlet louver zone is shown at 15. First fill sheet 10 isshown to be of a generally rectangular and generally planar structure;however, it should be understood that based on design of installationneeds first fill sheet 10 may be of a square or trapezoidal structure aswell. First fill sheet 10 is seen to comprise a top edge 11, bottom edge12, first side edge 18, and second side edge 14. Cooling air typicallyenters from the direction of first side edge 18 and travels and exitstowards the general direction of second side edge 14. Included in firstfill sheet 10 is first inlet louver zone 15 extending from first inletedge 18 to first transition edge 13. It is noted that first transitionedge 13 may be straight or curved. First inlet louver zone 15 is shownto be of a generally rectangular and generally planar structure;however, it should be understood that based on the design ofinstallation needs first inlet louver zone 15 may be of a square ortrapezoidal structure as well. First inlet louver zone 15 extends fromfirst side edge 18 to first transition edge 13 and from top edge 11 tobottom edge 12. Generally, when installed in a direct heat exchangeunit, possibly as a component of a cooling tower, evaporative liquid,usually water, flows downwardly onto top edge 11 and across first fillsheet 10, and exits bottom edge 12. First side edge 18 is typically anair inlet edge wherein air is forced or drawn cross-current to theevaporative liquid downward flow to exit from second side edge 14. Suchcombination of evaporative liquid generally flowing down andcross-current air flow acts to remove heat from the evaporative liquidby both a heat and mass transfer operation. It should be understood thatair flow may be somewhat counter current or con-concurrent with theevaporative liquid downward flow, depending on the design of the directheat exchange unit.

Each first fill sheet 10 including first inlet louver zone 15 is usuallycomprised of polyvinyl chloride, polypropylene, or any other plasticsheet formed in a press, vacuum forming, or molding operation.

First fill sheet 10 is seen to comprise of a plurality of first fillsheet ridge 34 on the rear surface of first fill sheet 10 extending fromfirst transition edge 13 to second side edge 14. Alternating with firstfill sheet ridges 34 are first fill sheet grooves 35.

First inlet louver zone 15 is also seen to comprise of a plurality offirst ridges 20 extending length wise from first side edge 18 to firsttransition edge 13 matching the shapes of a plurality of first fillsheet ridge 34. Alternating with first ridge 20 are first grooves 21,which also extend lengthwise across first inlet louver zone 15 fromfirst side edge 18 to first transition edge 13 at an inclined angle.

Referring now to FIG. 2, FIG. 2a , and FIG. 2b , first fill sheet 10 isshown and first louver zone 15 is also seen to comprise a first maleindexer 30, first male separators 31, and first recessed ridges 32. FIG.2a is an enlarged figure of an area near first male indexer 30, and FIG.2b is an isometric view of an enlarged figure of an area near first maleindexer 30.

A plurality of alternating first groove 21 and first ridge 20 cover mostof first louver 15. Connecting a plurality of first ridge 20 to aplurality of first groove 21 are a plurality of air tunnel walls 38.

First male indexer 30 extends upwardly from one of a plurality of firstgroove 21 past the plane of a plurality of first ridge 20. The height offirst male indexer 30 is discussed more in FIG. 6A description section.

First male separator 31 extends upwardly from the plane of a pluralityof first groove 21 until the top flat surface of first male separator isflushed with first ridge 20. Each first male separator 31 is locatedgenerally in the middle of one of plurality of first ridge 20. Firstmale separator 31 are generally spaced from 3 to 6 inches apart.

First recessed ridges 32 extends upwardly from the plane of a pluralityof first groove 21 to slightly lower than a plurality of first ridge 20.There are two first guide walls 33 per each first recessed ridge 32.More about first guide wall 33 is discussed in FIG. 6A descriptionsection.

There are two first curved ridge cutouts 36 on each side of first maleindexer 30, and first curved ridge cutouts 36 are made by gauging outair tunnel walls 38 adjacent first male indexer 30 until a portion offirst ridge 20 is lowered to form locally lowered ridge 37. Firstrecessed ridge 32 and its two accompanying first guide walls 33 areshown clearly. The angle between first guide wall 33 and the plane ofthe plurality of first groove 21 is between 30° and 60°.

Referring now to FIG. 3, first fill sheet 10 is shown with a pluralityof first ridge 20 and first curved ridge cutout 36 on two adjacent firstridges 20 of first male indexer 30.

Referring now to FIG. 4, second fill sheet 40 is shown.

First fill sheet 10 and second fill sheet 40 could be identical.Therefore, details shown in FIG. 2a and FIG. 2b could also be applied tosecond fill sheet 40. By making these sheets identical and by stackingthem in the same orientation except one sheet slightly shifted fromanother so that an air gap could be formed between sheets as shown in US2015/0034277, the manufacturing cost could be reduced.

Similar to first fill sheet 10, second fill sheet 40 is a generallyrectangular, generally planar structure, having top edge 41, bottom edge42, first side edge 43, and second side edge 44.

Included in second fill sheet 40 is second inlet louver zone 50extending from first inlet edge 43 to transition edge 51 and from topedge 41 to bottom edge 42. It is noted that transition edge 51 may bestraight or curved. Second inlet louver zone 50 is seen to be quitesimilar to first inlet louver zone 15 in that second inlet louver zoneis shown to be of a generally rectangular and generally planarstructure; however, it should be understood that based on design ofinstallation needs second inlet louver zone 50 may be of a square ortrapezoidal structure as well.

Second fill sheet 40 including second inlet louver zone 50 is againquite similar or identical to first fill sheet 10 there to in beingcomprised of polyvinyl chloride, polypropylene, or any other plasticsheet made in a pressing, vacuum forming, or molding operation.

Further, second fill sheet 40 is seen to comprise a series of secondfill sheet ridges 45 on the front surface of second fill sheet 40 andalternating series of second fill sheet grooves 46 on the front surfaceof second fill sheet 40. Second fill sheet ridges 45 extend lengthwisefrom transition edge 51 to second side edge 44 and second fill sheetgrooves 46 extend lengthwise from transition edge 51 to second side edge44.

Second inlet zone 50 is seen to comprise a series of second ridges 52extending from first edge 43 to transition edge 51. Similarly, secondinlet zone 50 is seen to comprise a series of second groove 53 extendingfrom first edge 43 to transition edge 51. Second ridge 52 aligns withsecond fill sheet ridge 45 and second groove 53 aligns with second fillsheet groove 46.

Referring now to FIG. 5, second fill sheet 40 has second inlet louverzone 50, which is also seen to comprise a second male indexer 55, secondmale separators 56, and second recessed ridges 57.

Second male indexer 55 extends upwardly from the surface of second inletlouver zone 50. As to be further explained, second male indexer 55 istypically located on one of plurality of second grooves 53 on the frontsurface of second inlet louver zone 50.

Second male separator 56 extends upwardly from the surface of secondinlet louver zone 50. As to be further explained, the extended surfaceof second male separator 56 is typically flushed with the plane of aplurality of second ridge 52, and the center of second male separator 56is typically located on second ridge 52 on the front surface of secondinlet louver zone 50.

Second recessed ridge 57 extends upwardly from the surface of secondinlet louver zone 50 to slightly lower than second ridge 52. Secondguide wall 58 connects second groove 53 to second recessed ridge 57.

In practice, a fill arrangement in a direct heat exchange unit would becomprised of two fill sheets, first fill sheet 10 and second fill sheet40, located adjacent each other and repeated multiple times as needed toform a fill pack, which is a direct heat exchanger. Subsequently, twoinlet louver zones included in the two fill sheets would also be locatedadjacent each other and repeated multiple times as needed.

In many cases first fill sheet 10 and second fill sheet 40 could beidentical. By making these two fill sheets identical, one thermalforming mold could be used to produce both first fill sheet 10 andsecond fill sheet 40, and the manufacturing cost could be reduced.

Referring now to FIG. 6a , schematics are shown wherein a portion offirst inlet louver zone 15 is seen to be adjacent a portion of secondinlet louver zone 50. First inlet louver zone 15 has a plurality offirst ridges 20 and a plurality of first grooves 21. Second inlet louverzone 50 has a plurality of second ridges 52 and a plurality of secondgrooves 53.

First male indexer 30 is seen to extend from one of plurality of firstgroove 21 of first inlet louver zone 15 toward one of second recessedridges 57 of second inlet louver zone 50. During the assembly process ofstacking first inlet louver zone 15 and second inlet louver zone 50, asfirst male indexer 30 travels toward second inlet louver zone 50, secondguide wall 58 guides first male indexer 30 toward second recessed ridge57 thereby shifting aligning first inlet louver zone 15 to second inletlouver zone 50.

FIG. 6b shows the desired location of first inlet louver zone 15 withrespect to second inlet louver zone 50 where first male indexer 30contacting second recessed ridge 57. Air travels through a plurality ofair tunnels 60 created by adjacent first inlet louver zone 15 and secondinlet louver zone 50, but for air tunnel 62 that is partially blocked byfirst male indexer 30 a pair of first curved ridge cutouts 36 allows airto go around first male indexer 30 through enlarged air passageway 63without significant air pressure drop. Each of first curved ridgecutouts 36 also creates an air bypass opening 61 between one of locallylowered ridges 37 and one of plurality of second groove 53 on eitherside of male indexer 30 so that air traveling inside two adjacent airtunnels 60 can enter air tunnel 62 and equalize the air pressuredifference among three air tunnels.

What is claimed is:
 1. An indexing feature for louvers in a direct heatexchanger, the indexing feature comprising: a first louver zone having aplurality of spaced ridges and grooves, a second louver zone adjacentthe first louver zone and having a plurality of spaced ridges andgrooves, wherein the ridges of the first louver zone are aligned withand adjacent the grooves of the second louver zone thereby forming aplurality of air tunnels between the first louver zone and the secondlouver zone; a recessed ridge of one of the ridges of the second louverzone, the one ridge forming at least a portion of one of the airtunnels; two guide walls of the one ridge of the second louver zoneextending from the recessed ridge toward adjacent grooves of the secondlouver zone; a male indexer of the first louver zone extending from oneof the grooves of the first louver zone to the recessed ridge of thesecond louver zone, the one groove forming at least a portion of the oneair tunnel; air passageways between the male indexer and the adjacentguide walls; two locally lowered ridges, each locally lowered ridgehaving a portion lowered by a respective curved ridge cutout and beingsituated in the first louver zone adjacent the male indexer and onopposite sides of the male indexer, two grooves of the second louverzone adjacent the recessed ridge and on opposite sides of the recessedridge; each of the curved ridge cutouts of the first louver zone areadjacent one of the grooves of the second louver zone; and a pair of airbypass openings each defined at least in part by one of the locallylowered ridges of the first louver zone and the adjacent groove of thesecond louver zone that permit airflow between the one air tunnel andadjacent air tunnels.
 2. The indexing feature of claim 1 wherein thecurved ridge cutouts each include an arcuate surface that guides airaround the male indexer.
 3. The indexing feature of claim 1 wherein thecurved ridge cutouts start near a base of the male indexer and open uptoward a plane of the plurality of ridges at an angle of 30 to 60degrees.
 4. The indexing feature of claim 1 wherein the two locallylowered ridges of the first louver zone each include a curved, upperedge.
 5. The indexing feature of claim 1 wherein the male indexerincludes a convex outer surface and the curved ridge cutouts eachinclude a concave surface facing the convex outer surface of the maleindexer.
 6. The indexing feature of claim 1 wherein the plurality ofridges of the first louver zone contact the plurality of grooves of thesecond louver zone.